Telephone system.



W. A. FRIGKE.

TELEPHONE SYSTEM. APPLICATION FILED MAY 10, 1909.

1,016,617, Patented Feb. 6, 1912.

A TTORNE Y UNITED STATES PATENT OFFICE.

WILLIAM A. FRICKE, OF CHICAGO, ILLINOIS, ASSIGNOR TO IVIONARCH TELEPHONE MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE SYSTEM.

To all whom it may concern:

Be it known that I, WILLIAM A. FRIOKE, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful ln'iprovement in Telephone Systems, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to telephone exchange systems, and particularly to that class of telephone exchange systems in which a common or central source of energy is employed at the exchange for operating the line signal and which source of current is normally connected with the telephone line, whereby the line signaling apparatus may be operated when the switch-hook is elevated or operated upon the removal of the telephone receiver. In accordance with my invention, I provide at such calling station a normally continuous metallic conductor of high resistance and serving to unite the sides of the telephone line, a signal-receiver being includedor associated with said high resisttance conductor, the resistance of the high resistance conductor serving to prevent the operation of the line signaling apparatus when the conductor controlled by the switch hook is open, a source of uni-directional current being associated with the telephone line and which is cooperatively related with switching mechanism at the exchange that serves to bring said source of uni-directional current into circuit relation with the telephone line to operate the signal-receiver at the telephone station.

Another feature of my invention relates to party telephone lines. In one embodiment of the invention as applied to party telephone lines, I employ two party line telephone stations equipped as above described, the signalreceiver at one party line station being responsive only to signaling current of negative sign from said source of uni-directional current, while the other signal-receiver is adapted to respond to current of positive sign, the switching mechanism serving to direct current of proper sign to the selected one of the signal-receivers. In another embodiment of my invention, I also associate with the party telephone line an additional telephone station having a signal-receiver that is responsive only to alter- Specification of Letters Patent.

Application filed May 10, 1909.

Patented Feb. 6, 1912. Serial No. 495,104.

nating current. In another embodiment of the invention, I provide a fourth station, in which the signal-receiver is included in a grounded conductor extending from a mid portion of a high resistance conductor in bridge of the sides of the telephone line, this latter signal-receiver being also responsive to current from the source of unidirectional current.

The accompanying drawing diagrammatically shows the preferred form of my invention as applied to a four station party line which is diagrammatically illustrated in connection with a diagrammatically illustrated exchange.

I have shown my invention as applied to a party telephone line upon which there are four telephone stations, though I do not wish to be limited to the number of telephone stations that are to be associated with the line. At each of the telephone stations A, B and C, I have indicated a signal receiver, the telephonic apparatus being omitted at stations A, B, U, as the illustration thereof is not necessary to an understanding of the invention. At the party telephone line station D, however, I have indicated a telephone transmitter a, a telephone receiver 7), and a switch-hook 0, the switch-hook, when supporting the telephone receiver, opening the bridge between the sides (Z and e of the party telephone line, said bridge in cluding the transmitter a and the telephone receiver 6, the switch-hook, when relieved of the weight of the telephone receiver 5, establishing such bridge. The telephonic apparatus at each of the stations A, B, C may be similar to that illustrated at the station D, and may have similar circuit relation with the sides of the party line the circles a indicating the location of the telephonic apparatus. The sides (Z, a of the party telephone line are shown as extending to a multiple switch-board, said sides terminating in line-jacks f f and an answeringjack It is to be understood, however, that I do not limit myself to multiple switch-board prac tice. Suitable signal appliances, including the line-relay h and the cut-oif relay 2', are shown in association with the party telephone line in a manner which is well understood by those skilled in the art. Cord-connecting apparatus, in this instance including an answering-plug 7t and a calling or connecting-plug Z, is shown, whereby a party telev the cord-circult.

phone line may be connected with another telephone line, but it is to be understood that I do not limit myself to a cord-connecting outfit employing a plurality of plugs. In the system illustrated, I have shown a wellknown form of supervisory apparatus associated with the answering and connectingends of the cord-circuit, this supervisory apparatus including a calling subscribers relay m, a calling subscribers supervisory lamp n, a called subscribers supervisory relay 0, and a called subscribers signal lamp p. Further description of the supervisory apparatus will be unnecessary, as the drawing clearly indicates the relation thereof to Four calling keys are shown in association with the connecting end of the cordcircuit, key A corresponding to the signalreceiver 9 at station A, key B corresponding to the signal-receiver r at station B, key C corresponding to the signal-receiver s at station G, and key D corresponding to the signal-receiver t at station D. The signal-receiver g at station A is in bridge between the sides d, e of the party line, the bridge including the signal-receiver Q desirably possessing one thousand ohms resistance, which is preferably disposed substantially entirely upon the signal-receiver g. The bridge containing the signal receiver q desirably also includes a condenser 9, so that direct current will not be permitted to pass through the signal-receiver g. The key A when operated, includes a source of alternating current 9 in serial relation with the sides d, e of the party line (assuming the calling-plug Z engages one of the jacks of said party line), the signal-receiver 9 being constructed to respond to the alternating current emanating from the generator 9 which preferably furnishes current at ninety volts pressure, to which end said signal-receiver, which is preferably a signal-bell structure, includes a polarized operating electro-magnet constructed similarly to the operating electro-magnets of signal-bells found at subscribers stations. The source of direct or uni-directional current a at the central exchange, which preferably furnishes current at one hundred forty volts pressure, is adapted to have varying associations with the party line through the instrumentality of the keys B C D the key B serving to connect the positive side of the battery it with the lower side 0 of the party line and the negative side of the battery with the upper side (Z ofthe party line, whereby the signal-bell r of station B, which is included in a bridge that it itself controls, is subject to the action of direct current of positive sign to which said signal-bell is adapted to rerespond, direct current of positive sign causing the armature of the signal-bell 1" to move in a clockwise direction, said armature, as a consequence of this movement, thereafter breaking, at 1', the bridge including the signal-receiver 1, the bridge being maintained closed at 1 a sufiicient length of time to permit the armature in its clockwise movement to sound the bell. After the circuit is broken at 1*, the spring r mechanically returns said bell-armature to its original position, by moving said a1.- mature in a counter-clockwise direction, and again causes the bell to sound, the bell structure including two gongs between which the clapper 1 carried by the armature, oscillates. In order that the signalreceiver 0" may respond to current of positive sign, it is properly polarized. The signal-receiver s at station C is desirably of a construction that is identical with the signal-receiver at station B, with the exception that the signal-receiver at station C is polarized to respond to current of negative sign when the key C is actuated, the key C serving to connect the negative pole of the battery u with the side a of the party line and the positive pole of said battery with the side (Z of the party line, the keys 13, C thus serving, one to connect the battery with the party telephone line d, c in one direction, and the other to connect said battery with said party telephone line in the reverse direction.

It will not be necessary to describe the component parts and the circuit relations of the signal-receiver s, the circuit relations of the receivers 1* and 8 being identical, each signal-receiver being included in a bridge whose continuity is controlled thereby, the two receivers having, as stated, no distinctions so far as their circuit relations are concerned, the only distinction being in their polarization, the receiver 1" responding to current of positive sign and the receiver s responding to current of negative sign.

The construction of the signal-receiver t is preferably identical with the construction of the signal-receivers r and s, but its circuit relation with the party telephone line is different from the circuit relation of the signal-receivers a" and s of the party telephone line. The signal-receiver I; may be arranged to respond to current of positive or negative sign, the signalereceiver t in the arrangement shown being adapted to respond to current of positive sign. The circuit arrangement of the signal-receiver t differs from the circuit arrangement of the signal-receivers 1", s, in that with the arrangement of the signal-receiver t the signaling current is caused to pass over but one of the sides d, e of the party line (in this instance the side 6), the current being returned by a third conductor whose continuity is established when the key D is actuated, this third conductor preferably including the ground connections '0.

My invention, in one of its aspects, relates particularly to common battery or central energy systems, in which a battery to is employed for signaling purposes. I have shown a common battery 20 which is not only adapted for signaling purposes, but may also be adapted, if desired, to supplying the transmitters a at the party line stations with talking battery current. The common bat tery w is normally connected in circuit relation with both limbs (Z, c of the party telephone line, whereby a subscriber at either of the stations A, B, C, D, in taking his tele phone receiver from its switch-hook, in order to signal the operator, completes circuit for said battery 10 at his switch-hook by closing the low resistance conductor including the telephone receiver, said battery w, owing to its relationship with the line and the relay it occasioning the operation of the party telephone line signal m. The inter-relation of the battery w, the relays h and i, the linesignal 00, and the cord-connecting outfit, is well illustrated, and is well known to those skilled in the art and needs no further description. The central source of energy to, also, in the embodiment of the invention illustrated, supplies the transmitter a at a calling party line station with current. The condenser g in the bridge at station A which includes the signal-receiver serves to pre vent the passage of direct current from the battery to through said bridge, and also serves to prevent the passage of direct current from the battery it when applied to the line by means of either of the keys B C The signal-receivers r and s at stations B, G are included in bridges which are metallically continuous, in order that current from the source a may operate said signalreceivers. In order to reduce the flow of current from the battery it; across the bridges including the signal-receivers r and s, which bridges are normally closed, said bridges are made of very high resistance, resistances w being included in said bridges, which are desirably of forty-four thousand ohms each, the magnets of the signal-re ceivers a" and 8 being each desirably wound to six thousand ohms. The signal-receiver 2,

includes an electro-magnet which is also desirably wound to six thousand ohms resistance, the ground connection from the side 6 of the party telephone line including a very high resistance 3 which is preferably of forty-four thousand ohms. In order to balance the party line, a resistance at station D is connected with the ground 1; at station D, the circuit for the signal-receiver t including a connection which is common to the inner terminals of the resistances y, y this connection extending to the ground 4) at station D, through the magnet of the signalreceiver 25, the armature of said signal-receiver and the contact a in normal engagement with said armature. As the party telephone line is thus connected by the resistances y, 3 another closed path is normally present for completing circuit for the battery w. -The resistances 2 3 together, in the preferred embodiment of the invention, aggregate eighty-eight thousand ohms, and the resistances in each of the bridges at stations B, C each includes fifty thousand ohms of resistance, so that though there are several conductors in metallic bridge of the party telephone line at the party line stations that establish circuit for the battery w, said conductors are of such high resistances asto make the flowof current from the battery to over the line when the line is not in use, negligible, as will be readily understood by those skilled in the art, particularly when it is remembered that the source of current to preferably is a twenty-four volt battery. If the battery in is grounded, and it is preferred to ground said battery at 'w the ground '1: at station D will not cause an excessive flow of current from the battery to when the party telephone line is idle, inasmuch as the grounded circuit for the battery to, including the ground 10 and the ground a at station D, includes the high resistance g Thus all of the paths that are closed to current from the battery w at the party line stations B, C, D are of such high resistance, that though these paths are in multiple relation with the battery w, the flow of current from said battery is so small, when the line is idle, as to be unobjectionable from a practical commercial standpoint.

While I have herein shown and particularly described the preferred embodiment of my invention, I do not wish to be limited to the precise arrangement shown, as changes may readily be made without departing from the spirit of my invention, but,

Having thus described my invention, I claim as new and desire to secure by Letters Patent the following 1. A common battery telephone exchange system including a telephone line extending from two telephone stations to an exchange; a conductor of high resistance in bridge of the line at each telephone station; polarized signal receivers in said high resistance conductors that are responsive to uni-directional current of opposite polarity; switching mechanism at the exchange for effecting the passage of unidirectional current over the line in different directions suited to the signal receiver that is to be operated; signaling apparatus and a source of current at the exchange adapted for inclusion in circuit with the line, the exchange signaling apparatus being prevented from operating by the high resistance conductors at the aforesaid stations; and a conductor of low resistance at each of said stations governed by the switch hooks thereat and opened when the switch hooks support the telephone receivers and closed when the switch hooks are free of the telephone receivers to shunt the high resistance bridge conductors and thereby occasion the operation of said exchange signaling apparatus.

2. A common battery telephone exchange system including a telephone line extending from two telephone stations to an exchange; a conductor of high resistance in bridge of the line at each telephone station; polarized signal receivers in said high resistance conductors that are responsive to uni-directional current of opposite polarity; switching mechanism at the exchange for efi'ecting the passage of uni-directional current over the line in different directions suited to the signal receiver that is to be operated; a third telephone station to which the tele phone line extends; a high resistance bridge conductor at this third telephone station; grounded connection from an intermediate portion of this high resistance conductor; a signal receiver included in this grounded connection; means at the exchange for including a source of signaling current in grounded circuit with the signal receiver at the third station; signaling apparatus and a source of current at the exchange adapted for inclusion in circuit with the line, the exchange signaling apparatus being prevented from operating by the high resistance conductors at the aforesaid stations; and a conductor of low resistance at each of said stations governed by the switch hooks thereat and opened when the switch hooks support the telephone receivers and closed when the switch hooks are free of the telephone receivers to shunt the high resistance bridge conductors and thereby occasion the operation of said exchange signaling apparatus.

3. A common battery telephone exchange system including a telephone. line extending from a telephone station to an exchange; a conductor of high resistance in bridge of the line at the telephone station; a signal receiver in said high resistance conductor; a second telephone station to which the telephone line extends; a high resistance bridge conductor at this second telephone station; a grounded connection from an intermediate portion of this high resistance conductor; a signal receiver included in this grounded connection; means at the exchange for including a source of signaling current in grounded circuit with the signal receiver at the second station and a source of signaling current in metallic circuit with the signal receiver at the first station; signaling apparatus and a source of current at the exchange adapted for inclusion in circuit with the line, the exchange signaling apparatus being prevented from operating by the high resistance conductors at the aforesaid stations; and a conductor of low resistance at each of said stations governed by the switch hooks thereat and opened when the switch hooks support the telephone receivers and closed when the switch hooks are free of: the telephone receivers'to shunt the high resistance'bridge conductors and thereby occasion the operation of said exchange signaling apparatus.

4:. A common battery telephone exchange system including a telephone line extending from two telephone stations to an exchange; a conductor of high resistance in bridge of the line at each telephone station; polarized signal receivers in said high resistance conductors that are responsive to uni-directional current of opposite polarity; the signal receivers at the aforesaid stations be ing included in circuit with switches that are provided with means for normally closing these signal receiver circuits and which switches are operated by the signal receivers to open the signal receiver circuits; switching mechanism at the exchange for efit'ecting the passage of uni-directional current over the line in different directions suited to the signal receiver that is to be operated; signaling apparatus and a source of current at the exchange adapted for inclusion in circuit with the line, the exchange signaling apparatus being prevented from operating by the high resistance conductors at the aforesaid stations; and a conductor of low resistance at each of said stations governed by the switch hooks thereat and opened when the switch hooks support the telephone receivers and closed when the switch hooks are free of the telephone reeeivers to shunt the high resistance bridge conductors and thereby occasion the operation of said exchange signaling apparatus.

5. A common battery telephone exchange system including a telephone line extending from two telephone stations to an exchange; a conductor of high resistance in bridge of the line at each telephone station; polarized signal receivers in said high resistance conductors that are responsive to uni-directional current of opposite polarity, the signal receivers at the aforesaid stations being included in circuit with switches that are provided with means for normally closing these signal receiver circuits and which switches are operated by the signal receivers to open the signal receiver circuits; switching mechanism at the exchange for eitecting the passage of uni-directional current over the line in ditterent directions suited to the signal receiver that is to be operated; a third telephone station to which the telephone line extends; a high resistance bridge conductor at this third telephone station; a grounded connection from an intermediate portion of this high resistance conductor; a signal receiver included in this grounded connection; means at the eX- change for including a source of signaling current in grounded circuit with the signal receiver at the third station; signaling apparatus and a source of current at the exchange adapted for inclusion in circuit with the line, the exchange signaling apparatus being prevented from operating by the high resistance conductors at the aforesaid stations; and a conductor of low resistance at each of said st'ations governed by the switch hooks thereat and opened when the switch hooks support the telephone receivers and closed when the switch hooks are free of the telephone receivers to shunt the high resistance bridge conductors and thereby occasion the operation of said exchange signaling apparatus.

In witness whereof, I hereunto subscribe my name this 8th day of May A. D., 1909.

WILLIAM A. FRICKE. Witnesses:

Gr. L. CRooG, L. G. STROI-I.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

' Washington, D. G. i 

